This invention pertains to a separation process. In particular, it pertains to a liquid extraction process for the separation of diesters.
In chemical operations it is often desirable to separate diesters from a solution that includes diesters, the corresponding monoesters and acids, diols and water. For example, in a process for the continuous production of a diol from a diol ester as disclosed in U.S. Pat. No. 3,917,720, the effluent stream from the reactor contains water, acetic acid, diol, monoesters, and diesters. The diesters are removed from the effluent stream by first flashing off the water and acetic acid and then extracting esters from the remaining mixture using a chloroform/water mixture as solvent.
The present invention provides an improved method for the solvent extraction of diesters from mixtures comprising diesters, the corresponding monoesters and acids, diols and water with solvents that selectively extract diesters from mixtures containing same.
Thus, one object of the present invention is to provide an energy efficient method for separating diesters from complex mixtures containing same.
Another object of the invention is to provide a process for separating diesters from liquid mixtures, which utilizes relatively inexpensive equipment.
A further object of the invention is to provide a process for the solvent recovery of diesters from mixtures containing same.
Still another object of the invention is to provide an improved process for the separation of diesters from diol reaction products.
A still further object of the invention is to efficiently remove diester impurities from diol reaction products containing same.
A still further object of the invention is to provide a one-step process for the solvent extraction of diesters.
Other objects of the invention will become apparent to those skilled in the art by studying this disclosure.